Ignition delay of stagnation-point oxidizing flows over a wall with the injection of fuel is analyzed numerically. The validity of various criteria of ignition delay, i.e., the adiabaticity criterion and the thermal runaway criteria (partial derivative(2) T-max/partial derivativet(2) = 0 and partial derivative(2)omega(max)/partial derivativet(2) = 0), is investigated for the problems of cold flow/hot wall and hot flow/cold wall. For cold flow/hot wall systems, the ignition delay decreases with the mass flux of fuel (m(w)) if m(w) is below a critical value (m(w,c)). The ignition delay is kinetically controlled for m(w) < m(w,c). For m(w) > m(w,c), the ignition delay increases with m(w) and is diffusionally controlled by the deficient oxidizer. The adiabaticity criterion is suggested from the viewpoints of practice and simplicity. For hot flow/cold wall systems, the ignition delay decreases with m(w) and is diffusionally controlled by the deficient fuel. The criterion of partial derivative(2)omega(max)/partial derivativet(2) = 0 is suggested both qualitatively and quantitatively. In addition, the effects of flow strain rate, Lewis numbers and Prandtl number on ignition delay are investigated.